1. Field of the Invention
The invention relates to a female terminal and a production method for a female terminal.
2. Description of the Related Art
Japanese Unexamined Patent Publication No. H09-63676 discloses a known female terminal into which a bar-shaped male terminal is fittable. The female terminal includes a substantially cylindrical terminal accommodating portion extending in forward and backward directions, and slits extending back from the front edge of the terminal accommodating portion. The slits are formed by slotting, and are arranged radially about an axial center of the terminal accommodating portion. The slits divide the terminal accommodating portion into a plurality of contact pieces that surround and press the male terminal when the male terminal fitting is fit in the terminal accommodating portion. Thus, the male and female terminals are connected electrically conductively.
The female terminal is formed using a round bar material. As shown in FIG. 23, a terminal connection hole 2 is formed in a round bar material 1, and the round bar material 1 is cut back from the front end thereof to form slits 3. The slits 3 form a plurality of contact pieces 4 around the terminal connection hole 2. Subsequently, as shown in FIG. 23, spinning is applied to the respective contact pieces 4 to bend base ends of the respective contact pieces 4 inwardly. A contact 5 is formed by leading end portions of the respective contact pieces 4 and an inner diameter of the contact 5 is smaller than an outer diameter of the male terminal. Thus, the respective contact pieces 4 are deformed resiliently out by the male terminal and the male terminal is pressed into contact with the contact 5 due to the resilient restoring forces of the respective contact pieces 4 when the male terminal is fit into the female terminal.
However, the finished shape of the contact portion 5 may be disrupted due to the spinning that is applied to the respective contact pieces 4. In other words, the finished shape of the contact portion 5 is likely to vary even if the influence of springback and the like is considered in an effort to obtain a predetermined finished shape by spinning. Thus, a contact area of the contact portion 5 and the male terminal may become smaller to increase contact resistance. Further, specifications may require a controlled standard interval t between the respective contact pieces 4 in the contact portion 5. However, the application of spinning to the respective contact pieces 4 will result in a larger variation of the interval t. Therefore, it has been difficult to produce a female terminal to meet the specification for the interval t. Hence, a production method for forming a female terminal only by a cutting process with high machining accuracy has been much needed for the production of a female terminal.
Spaces that separate the circumferentially adjacent contact pieces of the above-described female terminal are formed only by the long narrow slits. Foreign matter that may enter an accommodation space surrounding the contact pieces is not easily discharged through the slits. Thus, foreign matter may accumulate in the accommodation space to reduce connection reliability.
The present invention was developed in view of the above situation and an object thereof is to make a foreign matter easily dischargeable to the outside even if the foreign matter enters an accommodation space surrounded by a plurality of contact pieces.